Crystal indexing fixture

ABSTRACT

A crystal boule indexing fixture, the fixture comprising a frame including a pair of spaced apart, axially extending bores having parallel axes, and a pair of rods extending through the bores. A cover is hingedly connected to the frame through a hinge pin having an axis parallel to the axis of the bores, the cover being movable between a first position overlying a portion of the rods to press a crystal boule against the rods and a second position to increase the spacing of the cover from the rods so as to permit entrance to and egress from the fixture of such a boule. A lever projects from the cover and is biased so as to maintain the cover in its first position. Means are also provided to engage the lever to override the biased cover to lift the cover into the second position to facilitate entry and removal of the crystal boule.

Guggenheim Sr. et a1.

[451 Dec. 24, 1974 CRYSTAL INDEXING FIXTURE [75] Inventors: RobertClifton Guggenheim Sr.,

Poughkeepsie; Frank Victor Liucci, Wappingers Falls, both of NY.

[73] Assignee: international Business Machines Corporation, Armonk, NY.

22 Filed: Nov. 9, 1972 21 Appl. No.2 305,018

[56] References Cited UNITED STATES PATENTS 394,793 12/1888 Stoecklin 1.269/196 2,114,978 4/1938 Horger et al 82/38 2,382,257 8/1945 Ramsay 51/32,416,703 3/1947 51/217 A X 2,421,349 5/1947 ..51/l65.77 X 2,960,97811/1960 125/13 R 3,039,235 6/1962 Heinrich 51/73 R 3,085,370 4/1963Dietz 51/92 R 3,154,990 11/1964 Woods 83/414 3,168,893 2/1965 Johnson125/13 R 3,300,205 l/1967 Fitzpatrick 2 69/236 X 3,302,285 2/1967 Mann3,432,973 3/1969 Heinrich 3,662,733 5/1972 Okamoto 51/73 R X OTHERPUBLICATIONS American Machinist, May 12, 1952, p. 179, Cam Clamp.

Primary ExaminerAl Lawrence Smith Assistant ExaminerMarc R. DavidsonAttorney, Agent, or Firm-William 1. Dick [57] ABSTRACT A crystal bouleindexing fixture, the fixture comprising a frame including a pair ofspaced apart, axially extending bores having parallel axes, and a pairof rods extending through the bores. A cover is hingedly connected tothe frame through a hinge pin having an axis parallel to the axis of thebores, the cover being movable between a first position overlying aportion of the rods to press a crystal boule against the rods and asecond position to increase the spacing of the cover from the rods so asto permit entrance to and egress from the fixture of such a boule. Alever projects from the cover and is biased so as to maintain the coverin its first position. Means are also provided to engage the lever tooverride the biased cover to lift the cover into the second position tofacilitate entry and removal of the crystal boule.

15 Claims, 3 Drawing Figures CRYSTAL INDEXING FIXTURE The purpose ofthis abstract is to enable the public and the Patent Office to determinerapidly the subject matter of the technical disclosure of theapplication. This abstract is neither intended to define the inventionof the application nor is it intended to be limiting as to the scopethereof.

SUMMARY OF THE INVENTION AND STATE OF THE PRIOR ART The presentinvention relates to an indexing fixture, and more particularly relatesto a crystal boule indexing fixture to be utilized on or in conjunctionwith crystal slicing saws.

Saws for cutting crystal boules, such as boules of silicon andgermanium, have been employed in the electronics industry for a numberof years. One of the principal saws employed is of the type manufacturedby Hamco Machine and Electronics Corporation, and is typified in US.Pat. No. 3,039,235 issued on June 19, 1962 to the aforementionedassignee. In these saws which may be categorized as hole saws, the sawblade takes the form of a thin flat annulus which is provided with acutting edge at the inner periphery of the annulus. The crystal is movedagainst the edge at a variable rate of movement to cut a thin slice fromthe crystal, and then the crystal is returned to the central portion ofthe annular cutting device, indexed downwardly a small increment, andthe cycle is repeated.

While there have been numerous holders employed for carrying the bouleso that it may be properly indexed into the hole for jutting purposes,and while the machine has been modified so as to permit properorientation of the crystal so that the cut or slice formed by thecutting operation will be along the proper crystallographic plane, suchholding fixtures have had, in the past, several disadvantages. For themost part the disadvantage has been the time required in adjusting thecrystal so that it is properly held in the holder while feeding thecrystal into the saw blade. Additionally, inasmuch as the crystal mustbe fed into the central opening of the annular cutting blade, theholders have of necessity required a certain degree of freedom to permitsliding of the boule downwardly into the annulus while resisting thetorque created by the moving blade as well as the torque created by themovement of the holder against the blade. Thus the boule must be heldfirmly so as to prevent radial shift thereof upon contacting the innerperiphery (cutting edge) of the annulus while still allowing a degree offreedom so that it may be indexed through the holder for subsequentslicing cuts.

Additionally, after a number of slices have been formed by cutting thecrystal boule with the slicing blade or device, it is sometimesbeneficial to dress the blade with, for example, a silicon carbidedressing stick. With present apparatus, it is necessary to apply aspecial fixture and jig to apply the dressing stick to the blade tothereby dress the blade. This, of course, takes additional time andreduces the machine throughput per work shift.

In view of the above it is a principal object of the present inventionto provide a novel crystal boule indexing fixture.

Another object of the present invention is to provide a crystal bouleindexing fixture which is readily adaptable to existing saws such ascrystal slicing hole saws.

Still another object of the present invention is to provide a crystalboule indexing fixture which will hold the crystal rigidly to preventlateral or radial displacement thereof as the crystal is being cut bythe cutting blade, but which will permit indexing of the crystallongitudinally of the fixture so as to permit repetitive placement ofthe crystal in a predetermined position for cutting slices ofsemiconductor crystal of uniform thickness.

Yet another object of the present invention is to provide a crystalindexing fixture which may be easily oriented so as to permit cutting ofthe crystal along any desired crystallographic plane.

Yet another object of the present invention is to provide a crystalboule indexing fixture in which a dressing stick may easily be mountedto facilitate ease of dressing of the cutting edge of the blade of themachine upon which the fixture is mounted.

Still another object of the present invention is to provide a fixturehaving a cover thereon to clamp the crystal in a predeterminedorientation relative to the machine while permitting ease of applicationof the cover to the boule and firm grasping of the boule whilepermitting the boule to be easily indexed.

Other objects and a more complete understanding of the invention may behad by referring to the following specification and claims taken inconjunction with the accompanying drawings in which:

FIG. 1 is a fragmentary front elevational view illustrating a crystalboule indexing fixture constructed in accordance with the presentinvention;

FIG. 2 is a fragmentary side elevational view of the fixture illustratedin FIG. 1; and

HG. 3 is a fragmentary bottom view of the apparatus illustrated in FIGS.1 and 2.

Referring now to the drawings, and more specifically FIG. 1 thereof, acrystal boule indexing fixture 10, constructed in accordance with thepresent invention, is illustrated therein. As shown in the drawing, thefixture 10 includes a frame 11 having a central body portion 12 andprojecting flange portions 13 and 14 extending from the body 12. Theflange portions 13 and 14 include a pair of arcuate slots 13A and 14Arespectively, which with bolts 15 and 16 serve to position the fixture10 at a desired angle (in the plane of the paper) relative to a verticalaxis, on the frame 17 of a cutting machine.

In accordance with the invention means are provided on the fixture toeffect a three point location of a crystal boule 20 to grasp the boulefirmly so as to prevent tortional motion or movement of the boule ascutting is effected while permitting indexing of the boule forsubsequent cuts as by a saw blade 18 rotating in the machine 19. To thisend, and referring now to FIGS. 2 and 3, the body 12 of the frame 11includes upper and lower pedestal portions 21 and 22 respectively eachhaving a pair of spaced apart axially extending bores 23 and 24 therein,the bores having parallel axes and housing therein upstanding rods 25and 26 respectively. As shown best in FIG. 3, each of the pedestals 21and 22 includes a recessed portion 27 which permits the circumference orsurface of the rods to project outwardly away from the pedestals so asto permit engagement thereof by the surface of the boule 20. To preventlongitudinal displacement of the rods 25 and 26 in the bores 23 and 24,set screws 25A and 26A are utilized to grasp the rods to the body of theframe 11.

In order to clamp the boule against the rods while permitting axial orlongitudinal displacement of the boule therein, a quick release cover 30is hingedly connected to the frame and movable between a first positionoverlying a portion of the rods to press a crystal boule against therods and a second position to increase the spacing of the cover from therods to permit entrance to and egress from the fixture of a crystalboule. To this end, and as illustrated in FIGS. 2 and 3, the cover 30 isgenerally arcuate in shape and subtends an angle of approximately 90 sothat its terminal end 31 substantially overlies a plane drawnperpendicular to a line joining the axes of the rods and 26. In thismanner the terminal end may capture the crystal boule 20 between thecover and the rods 25 and 26.

In most instances, to facilitate and maintain alignment of the crystalwhile permitting proper indexing thereof parallel to the axes of therods, as well as during the cutting operation, anti-torque means areprovided on the cover to mate with means on the boule to inhibitrotation thereof. To this end, a glass filled phenolic key 32 is bondedto the surface of the boule as with a semirigid epoxy, such as anEmerson Cummings EC-45 resin. The key registers, mates or coopreateswith a keyway 33 in the cover adjacent the terminal end 31 thereof.

As illustrated best in FIGS. 2 and 3, the pedestals 21 and 22 include aprojecting end portion having hinge pin 34 receiving apertures 29A and29B therein, in the illustrated instance the apertures 298 in each ofthe pedestals 21 and 22 connecting, through the hinge pin 34 and boredbosses 35 and 36, the cover 30. A handle 37 may be employed tofacilitate grasping of the cover In order to facilitate proper clampingof the cover on the boule 20, quick acting clamp means are provided tofacilitate moving of the cover between a first position overlying therods and pressing a crystal boule between the cover and the rods and asecond position wherein the cover is lifted away from the rods so as tofacilitate loading of the fixture with a boule. To this end, andreferring now to FIGS. 1, 2 and 3, the cover includes a projecting lever40 having a bored hole or aperture 41 therein to receive a post 42 whichis secured as by threads to the flange 13. Intermediate the flange andthe lever is biasing means, in the illustrated instance a heavy spring43 which tends to apply force about the hinge pin 34 against the leverand therefore tends to maintain the cover 30 in a position pressing theboule against the rods 25 and 26. To facilitate opening of the cover,against the bias of the spring 43, the post 42 is connected to a sleeve44 which fits intermediate a bifurcated cam 45 which is connected toactuating means, in the present instance a handle 46. Inasmuch as thesleeve is rigidly secured to the pin or post 42, while the bifurcatedcam 45 is connected to the sleeve by a shaft 47 which is free to rotatein the sleeve 44, motion of the handle downwardly, in the illustratedinstance away from the cover, causes the lobe 45A of the cam the engagethe upper surface of the lever effecting rotation of the cover 30 aboutthe hinge pin 34 and elevation of the cover into the second position.

To prevent inadvertent movement of the cover when the boule is inposition intermediate the cover and the rods 25 and 26, the sleeve 44 isprovided with a groove 48 therein, while the bifurcated cam includes abored hole 49 therein which permits the entry to and egress therefrom ofa locking pin 50.

In the event a larger crystal boule 20 is desired to be sliced, thehinge pin 34 may be removed from the apertures 29B and moved upwardly tothe apertures 29A, thereby accommodating an increased diameter crystalboule. As is evident to maintain at least the same closing pressure ofthe cover against the boule a different spring may be employed or theexisting spring may be shimmed to accommodate the increase in spacingbetween the flange and the lower surface of the lever 40. Additionally,a different cam and post may be neces sary, or if the threaded end is ofsufficient length, the post may simple be unscrewed from the flange 13as sufiicient distance to accommodate the spacing between the holes 29Aand 29B.

Often during cutting or slicing the operator will notice that theproduct being cut is receiving some surface defects usually due to anincrease in roughness of the blade, indicating that the blade requiresdressing or replacement. In such an event, with existing machines, it isnecessary to dismount the crystal indexing fixture, or in thealternative to at least place it out of use and in a position so as notto interfere with the dressing operation. With the fixture of thepresent invention, it is a simple matter to place the dressing tool onone of the flanges, for example the flange 14. To this end, a dressingfixture 51 may be employed, the fixture including a block 52 connectedto the flange 14 and dovetailed to receive a slide 53 thereon to whichis connected a dressing stick 54 as by a ring clamp or the like 55. Theslide may have a mating dovetail as at 56 and include a rack gear whichmates with a drive pinion 57 which permits elevation and depression ofthe dressing stick 54 towards and away from the blade 18 shownschematically in FIG. 1. The dressing stick may be composed of anysuitable dressing material, for example silicon carbide, and may easilybe adjusted as to the ring clamp 55 merely by loosening the ring clampand moving the stick downwardly as the stick is used.

Any typical conventional drive means may be employed to index thecrystal boule 20 downwardly to permit slicing of the boule. For example,as shown in FIG. 1, a drive means 65 may be employed including a leadscrew 66 or the like which is driven in a stepping fashion as by astepping motor or an air drive, the lower end of the lead screw 66abutting the crystal so as to effect axial displacement thereof alongthe guide rods between the cover and the guide rods.

Thus the present invention provides a simple and yet novel crystal bouleindexing fixture particularly adapted to existing saws.

Although the invention has been described with a certain degree offparticularity, it is understood that the present disclosure has beenmade only by way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts and the modeof operation may be made without departing from the spirit and the scopeof the invention as hereinafter claimed.

What is claimed is:

1. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly connected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; a lever projecting from said cover and means biasing saidlever to maintain said cover in said first position; and anti-torquemeans on said cover to mate with means on a crystal boule to inhibitrotation thereof, said anti-torque means comprising one of a key andkey-way, and said means on a crystal boule comprising the other of saidkey and key-way; and means to engage said lever to over-ride saidbiasing means to lift said cover into said second position.

2. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly connected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; said frame including a body portion and projecting flanges,and means defining arcuate slots in each of said flanges to permitadjustment of said body portion in a vertical plane; a lever projectingfrom said cover and means biasing said lever to maintain said cover insaid first position; and anti-torque means on said cover to mate withmeans on a crystal boule to inhibit rotation thereof, and means toengage said lever to over-ride said biasing means to lift said coverinto said second position.

3. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly cnnected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; a lever projecting from said cover and means biasing saidlever to maintain said cover in said first position; and anti-torquemeans on said cover to mate with means on a crystal boule to inhibitrotation thereof, and means to engage said lever to over-ride saidbiasing means to lift said cover into said second position, and a holderfor a dressing stick; and means to adjustably position said holder in adirection substantially parallel to said rods.

4. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly connected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; a lever projecting from said cover and means biasing saidlever to maintain said cover in said first position; and anti-torquemeans on said cover to mate with means on a crystal boule to inhibitrotation thereof, and means to engage said lever to over-ride saidbiasing means to lift said cover into said second position, andincluding drive means; and means for coupling said drive means to acrystal boule held intermediate said cover and rods to displace saidboule in a direction parallel to said rods and therealong.

5. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly connected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; a lever projecting from said cover and means biasing saidlever to maintain said cover in said first position; and anti-torquemeans on said cover to mate with means on a crystal boule to inhibitrotation thereof, and means to engage said lever to over-ride saidbiasing means to lift said cover into said second position; a hinge pinin said cover and means carrying said pin on said frame; and alternatehinge pin carrying means on said frame to displace said cover furtherfrom said rods than when said cover is in said first position.

6. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly connected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; a lever projecting from said cover and means biasing saidlever to maintain said cover in said first position; including cam meansbearing against said lever, and actuating means connected to said cammeans to effect motion to said lever against biasing means; andanti-torque means on said cover to mate with means on a crystal boule toinhibit rotation thereof, and means to engage said lever to over-ridesaid biasing means to lift said cover into said second position.

7. A crystal boule indexing fixture in accordance with claim 6 whereinsaid biasing means comprises a spring.

8. A crystal boule indexing fixture in accordance with claim 7 includinglocking means for maintaining said actuating lever in a predeterminedposition.

9. A crystal boule indexing fixture comprising: a frame including a bodyportion and a pair of projecting flanges, means for adjustably mountingsaid flanges to a surface; a pair of spaced apart, parallel, axiallyextending bores in said body portion; a pair of rods extending throughsaid bores, and a recess in said body exposing a portion of the surfaceof said rods; a cover hingedly connected to said frame and moveablebetween a first position overlying said exposed portion of said rods topress a crystal boule against said rods and a second position toincrease the spacing of said cover from said rods; means to bias saidcover to maintain said cover in said first position, and means toovercome said bias to effect movement of said cover into said secondposition.

10. A crystal boule indexing fixture in accordance with claim 9including means in said cover for gripping a crystal to inhibit rotationthereof.

11. A crystal boule indexing fixture in accordance with claim 10including a key way in said cover, said key way adapted for cooperatingwith a key on a crystal.

12. A crystal boule indexing fixture in accordance with claim 9including a holder mounted on one of said flanges, said holder includingmeans to position a dressing stick thereon, and means to adjustablyposition said holder in a direction substantially parallel to said rods.

means to efiect motion to said lever against said biasing means.

15. A crystal boule indexing fixture in accordance with claim 14including means for locking said actuating means in a predeterminedposition.

1. A crystal boule indexing fixture, said fixture comprising: a frameincluding a pair of spaced apart, axially extending bores havingparallel axes; a pair of rods extending through said bores, a coverhingedly connected to said frame and movable between a first positionoverlying a portion of said rods to press a crystal boule against saidrods and a second position to increase the spacing of said cover fromsaid rods; a lever projecting from said cover and means biasing saidLever to maintain said cover in said first position; and anti-torquemeans on said cover to mate with means on a crystal boule to inhibitrotation thereof, said anti-torque means comprising one of a key andkey-way, and said means on a crystal boule comprising the other of saidkey and key-way; and means to engage said lever to over-ride saidbiasing means to lift said cover into said second position.
 1. A crystalboule indexing fixture, said fixture comprising: a frame including apair of spaced apart, axially extending bores having parallel axes; apair of rods extending through said bores, a cover hingedly connected tosaid frame and movable between a first position overlying a portion ofsaid rods to press a crystal boule against said rods and a secondposition to increase the spacing of said cover from said rods; a leverprojecting from said cover and means biasing said Lever to maintain saidcover in said first position; and anti-torque means on said cover tomate with means on a crystal boule to inhibit rotation thereof, saidanti-torque means comprising one of a key and key-way, and said means ona crystal boule comprising the other of said key and key-way; and meansto engage said lever to over-ride said biasing means to lift said coverinto said second position.
 3. A crystal boule indexing fixture, saidfixture comprising: a frame including a pair of spaced apart, axiallyextending bores having parallel axes; a pair of rods extending throughsaid bores, a cover hingedly cnnected to said frame and movable betweena first position overlying a portion of said rods to press a crystalboule against said rods and a second position to increase the spacing ofsaid cover from said rods; a lever projecting from said cover and meansbiasing said lever to maintain said cover in said first position; andanti-torque means on said cover to mate with means on a crystal boule toinhibit rotation thereof, and means to engage said lever to over-ridesaid biasing means to lift said cover into said second position, and aholder for a dressing stick; and means to adjustably position saidholder in a direction substantially parallel to said rods.
 5. A crystalboule indexing fixture, said fixture comprising: a frame including apair of spaced apart, axially extending bores having parallel axes; apair of rods extending through said bores, a cover hingedly connected tosaid frame and movable between a first position overlying a portion ofsaid rods to press a crystal boule against said rods and a secondposition to increase the spacing of said cover from said rods; a leverprojecting from said cover and means biasing said lever to maintain saidcover in said first position; and anti-torque means on said cover tomate with means on a crystal boule to inhibit rotation thereof, andmeans to engage said lever to over-ride said biasing means to lift saidcover into said second position; a hinge pin in said cover and meanscarrying said pin on said frame; and alternate hinge pin carrying meanson said frame to dispLace said cover further from said rods than whensaid cover is in said first position.
 6. A crystal boule indexingfixture, said fixture comprising: a frame including a pair of spacedapart, axially extending bores having parallel axes; a pair of rodsextending through said bores, a cover hingedly connected to said frameand movable between a first position overlying a portion of said rods topress a crystal boule against said rods and a second position toincrease the spacing of said cover from said rods; a lever projectingfrom said cover and means biasing said lever to maintain said cover insaid first position; including cam means bearing against said lever, andactuating means connected to said cam means to effect motion to saidlever against biasing means; and anti-torque means on said cover to matewith means on a crystal boule to inhibit rotation thereof, and means toengage said lever to over-ride said biasing means to lift said coverinto said second position.
 7. A crystal boule indexing fixture inaccordance with claim 6 wherein said biasing means comprises a spring.8. A crystal boule indexing fixture in accordance with claim 7 includinglocking means for maintaining said actuating lever in a predeterminedposition.
 9. A crystal boule indexing fixture comprising: a frameincluding a body portion and a pair of projecting flanges, means foradjustably mounting said flanges to a surface; a pair of spaced apart,parallel, axially extending bores in said body portion; a pair of rodsextending through said bores, and a recess in said body exposing aportion of the surface of said rods; a cover hingedly connected to saidframe and moveable between a first position overlying said exposedportion of said rods to press a crystal boule against said rods and asecond position to increase the spacing of said cover from said rods;means to bias said cover to maintain said cover in said first position,and means to overcome said bias to effect movement of said cover intosaid second position.
 10. A crystal boule indexing fixture in accordancewith claim 9 including means in said cover for gripping a crystal toinhibit rotation thereof.
 11. A crystal boule indexing fixture inaccordance with claim 10 including a key way in said cover, said key wayadapted for cooperating with a key on a crystal.
 12. A crystal bouleindexing fixture in accordance with claim 9 including a holder mountedon one of said flanges, said holder including means to position adressing stick thereon, and means to adjustably position said holder ina direction substantially parallel to said rods.
 13. A crystal bouleindexing fixture in accordance with claim 9 including a lever projectingfrom said cover, and said biasing means being in operative engagementwith said lever.
 14. A crystal boule indexing fixture in accordance withclaim 13 including cam means bearing against said lever, and actuatingmeans connected to said cam means to effect motion to said lever againstsaid biasing means.
 15. A crystal boule indexing fixture in accordancewith claim 14 including means for locking said actuating means in apredetermined position.